I saw that one on another site,, those fellows are trained well. A buddy of mine was a forward air controller and on an exercise at Camp Pendelton, they rappelled from a chopper into an area at night, set up their post, and their Lt. told them to get some rack time before morning. When they awoke, they noticed how brushy it was in their zone, all at once the brush stood up, during the night a team of Ricky Recon, who were training in the area also, slipped in and just waited , their squad leader gave some quick hand signals and they disappeared into the brush without a word or sound. His Lt. told them he knew they were coming and it was their exercise to get in unnoticed, he still comments on how well those Marines were trained.

I manages to get three right, though it was mostly through guessing on two of those. If there was a man sized lump in the pic, I guessed it to be the sniper. Of course, that method only works if you know there's a sniper somewhere in the pic. Otherwise, I would have never even noticed them. In the third one, he wasn't hidden well since he's in a pretty flat/smooth area. One big lump kind of stands out.